This invention relates to quick disconnect couplings, and, more particularly, to a female quick disconnect coupling which requires a very low pull force to disconnect and a very low push force to connect.
Quick disconnect couplings are used, for example, to connect hydraulic fluid line hoses. A typical application is on agricultural tractors to connect the tractor hydraulic system with the attachable implements.
Over the years changes have occurred in tractor hydraulic systems which have required changes and performance improvements in the couplings. The invention provides a coupling which is improved over prior designs such as those shown in U.S. Pat. Nos. 4,077,433 and 4,303,098.
The major advantages of the inventive coupling over previous designs include:
1. A very low pull force is required to disconnect the coupling when it is pressurized with high internal hydraulic pressure.
2. Very low oil spillage occurs when disconnecting while a coupling is pressurized.
3. A very low push force is required to connect the coupling when either half or both halves are pressurized.
4. The female coupling can overcome trapped pressure in the male coupling half when the trapped pressure exceeds the pressure capability of the tractor output pressure.
5. A simple and unique method is provided for installing, retaining, and removing the cartridge assembly in the outer housing of the female coupling.
6. A unique seal retainer retains an elastomer seal under high pressure during opening and closing operations.
7. The female coupling can drain pressure relief fluid along with normal disconnect spillage to a remote location.